Researches of negative immunoregulation provide a new strategy for tumor treatment. In the tumor microenvironment, there exists a large amount of negative regulatory cells, which interact with and affect each other, accompanied with the co-evolution of tumor cell and microenvironment. Due to the change of immunogenicity and abnormal growth of tumor cells, fibroblasts are stimulated to release inflammatory factors, antigen-presenting cell deliver tumor antigen signal, to co-recruit immune cells to infiltrate into local tumor, and the abnormal proliferation of tumor cells causes the press on adjacent cells, causes tissue injury such as ischemic necrosis, producing a large amount of inflammatory factors, thus local tumor is in an uncontrolled inflammatory status, resulting in the generation of negative immunoregulation in the microenvironment, inducing the formation of cancer-associated fibroblast (CAF) and myeloid-derived suppressor cells (MDSC), IL10 and TGF-β induces macrophages to transform from killer M1 type into immunosuppressive M2 type; regulatory T cell is increased in the local tumor significantly. The result is inhibiting the activities of cytotoxic T cell (CTL), natural killer cell (NK), maintaining immunological tolerance status in the local tumor.
Researches in recent years show that, polysaccharide has a significant anti-tumor activity and has a rather small toxic side effect on human body, the study on the biological activity of polysaccharide has become the hotspot of research of experts and scholars at home and abroad in the medical field. Recent years, some polysaccharides and complex thereof are discovered as having significant efficacies on many diseases, such as immune disorders, cancer, diabetes, hypertension, hepatitis, blood clots, pneumonia, virus, and involving to the regulation of various living phenomena in the cell.
Cistanche deserticola belongs to endangered species in Orobanchaceae, is distributed in Inner Mongolia, Ningxia, Gansu and Xinjiang, and known as “desert ginseng”, it has a very high medicinal value, is the traditional rare and precious Chinese medicinal herbs in China, and is also one of the most frequently used tonic medicines in the Kidney-supplementing and Yang-invigorating prescription. Nowadays, there is not use of Cistanche deserticola as raw material to prepare polysaccharide, and use for preparing dietary supplement having effect of inhibiting colon cancer.